Sabine Tanios is a PhD candidate in Tasmania working on research into why and how potatoes develop green colouring.
Her work at the Tasmanian Institute of Agriculture looks at the wide range of factors that cause undesirable greening in potatoes, and at ways of reducing it.
She said consumers’ reluctance to eat green potatoes had an easy solution.
“We’ve all heard that green potatoes are toxic,” she said. “However, this is not true. When potatoes are exposed to light, they accumulate glycoalkaloids, which are known to be toxic compounds if they are consumed at high concentrations.”
But Tanios said this was not usually the case with green potatoes that were sometimes offered for sale.
Tanios’s research is looking into what causes the greening in potatoes in the field, as well as what affects the greening in retail stores. It also looks at the effects of nitrogen, the role of genetics and the impact of harvesting times on the greening of potatoes.
All about the light
“Light is the main factor affecting greening,” Tanios said. “Keeping potatoes in the dark is the key factor towards avoiding greening, but in the supermarket you cannot keep your potatoes in a black box.”
Research has revealed the colour or wavelength of light is a key factor.
“When you use blue light, greening can occur very quickly, while if you use green light, greening is much less,” Tanios said.
Greening occurs over a wide range of potato varieties, with more than 100 different types being screened as part of the research project, with some more susceptible than others.
Tanios said her research results would have a wide application.
“Potatoes are the fourth-most important food crop worldwide,” she said. “Greening is one of the major factors contributing to millions of dollars of losses every year in each country.”